It could be either way - some parents are forever criticizing their children in comparison with other children which is very bad for since it makes the child feel insecure and lose confidence in himself /herself...Either way we need to be careful while not comparing our children to other children nor to our own kids when there is more than one child in the family ..
Yeah...comparison between siblings is very very common due to which there is a lot of rivalry among children. Sometimes the rivalry is carried into adulthood too!
In some form relation oriented psychology should be taught in secondary level schools to sensitize students.
It should be taught..but sadly, our education curriculum does not contain anything remotely connected to sensitizing students!
In India we dont even have the system of having a counsellor,for which the initiative shd be taken by the government.Some private schools do have counsellors and it has proven very effective in tackling home related and teen problems that are comon among students...Most children seem to suffer from some complex or the oher and parents are the root cause of it.